Designing Online Transaction Processing System

Question

What factors do one need to watch for while designing online transaction processing system (around 450 transactions per second).
Thanks

Answer 1

Depending on the complexity of what you're calling a transaction and the interdependency of the information, sustaining 450 transactions per second may be a non-trivial exercise. If most of your transactions involve inserting or updating information you're application is likely to be IO bound.
You may want to prototype something that benchmarks raw throughput to your database and disk of choice. Meaning writing records that will approximate the size of what you'll be writing in your transactions. You'll need to find the right combination of number of Threads and transaction size that provides optimal throughput for your environment. Don't underestimate the importance of database tuning. If your prototype can't achieve the throughput you're looking for then you're final application will have no hope.
Recently I worked on an application with similar performance requirements. We prototyped and benchmarked raw throughput as I described above and were able to insert over 2000 200 byte records per second to our database. Our finished application sustains about 75% of that performance. This is on SMP hardware with high-end disk. Good luck.
-S